Electric stop mechanism.



No. 737,210. PATENTEDk AUG.25. 190s;-

s. G. COLT. v I BLEOTRIG STOP MECHANISM.

APPLICATION FILED BEPT. 23, 1901.

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No. 737,210. PATENTBD AUG. 25,1903;

' S. G. COLT.

ELECTRIC STOP MECHANISM.

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UNITED STATES Patented August 25, 1903.

PATE T OFFICE.

SAMUEL G. COLT, OF PITTSFIELD, MASSACHUSETTS, ASSIGNOR TO STANLEYELECTRIC MANUFACTURING COMPANY, OF PITTSFIELD, MASSACHU- SETTS, ACORPORATION OF NEW JERSEY.

ELECT-RIC STOP] MECHANISM.

SPECIFICATION forming part of Letters Patent No. 737,210, dated August25, 1903. Application filed September 23, 1901, Serial N o. 761168. (Nomodel.)

Pittsfield, Massachusetts, have invented oer-- tain new and usefulImprovemen ts in Electric Stop Mechanisnnof which the following is afull, clear, and exact description.

My invention relates to stop mechanism for gate-valves or other deviceshaving a defizo nitely-limited movement and operated by Inotors, and hasfor its object to provide a means for preventing injury to the gatevalveormotor through inattention of the attendant operating the motor. Thechief danger in the r 5 case of'valves lies in the fact that the instantthe valve becomestight shut or full open any continued operation of thegearing would be liable to result in thestripping of the threads on thevalve-stem or the breaking of nuts, and

thus rendering the valve useless or in injury to other parts of thesystem.

Since the motor is required to do workup to the very instant ,that'thevalve'becomes A tight shut or fully open, I avoid the danger z 5referred to above by disconnecting the motor from the gearing at thatparticular instant,

so that any further action on the part of the.

motor, even through the inertia of its armature, isnot transmitted tothe valve-stem.

The embodiment of my invention as applied to gate-valves is shown in theaccompanying drawings, in which Figure 1 is a side elevation. Fig. 2 isa plan view. Fig; 3 is a detail view. Fig. 4 is a de- 3 5 tail view, andFig. 5 a diagram of circuits.

Referring to the drawings more particularly, A represents an electricmotor supplied with current from any convenient source, having upon itsshaft an electromagnetic clutch 4o B,one member of which rotates withthe shaft, while the other is mounted so as to rotate freely thereon.

C, which engages with a gear D, attached to the shaft E, which, alsocarries the gear F.

The gear F meshes with the gear G, which transmits motion to the gear H,which in turn meshes with the gear I, mounted upon the valve-stem J, sothat when the electric clutch B is operated the movementof the motor Ais This second member carries a gear transmitted through the gears tothe valvestem J Upon the upper end of the shaft which carries the gearsG and H is a circuitbreaking device K, consisting of a worm L, whichoperates a gear L, by which motion is transmitted through bevel-gears Mto'a screw N,the, rotation of which causes the block 0, carrying theslide P, to move in one direction or the other. The slide P bears uponcon ducting-strips Q for the purpose hereinafter described.

- Referring to the diagram of circuits, 1 2 are mains from which thecurrent operating the motor is derived. These are connected to contacts3 3 of a double-throw switch S, which in one position connects thecontacts 4 5 and 4' 5, respectively,with the mains 1 and 2 and in theother position connects the contacts 6 7 and 6'7, respectively, with themains l and 2. From the terminals 5 and 7 the conductor T leads to oneof the armature-brushes, 8,theotherarmature-brush,8,beingconne'cted tothe terminals 5and 7 by the conductor V. The terminals 4 6 and 4 6 areconnected, respectively, to opposite terminals of the motor field-coilsby the conductors V and;- W. With these connections it will be seen.that the ing-switch. The field-magnet is connected so as to be ofthesame polarity whichever way the switch is thrown while the armatureconnections are reversed, so that throwing the switch S reverses thedirection of the motor. 9 is a starting-box in the armature-circuit usedin starting the motor from rest.

10 is a spring-retracted switch having one terminal connected with thecontacts 4 and 6 and whereby the circuit X, through the clutchenergizing coil 11, can be normally closed. The contact-pieces Q Q areelectrically connected to the conductors X and Wat 12 and 13, so thatwhen engaged by the slide P they also complete the circuit through theclutch-energizin g coil 11.

that the circuit for the clutch B may be completed in two diiferentwaysone by closing by hand the spring-retracted switch 10, and the otherthrough the slide P and contacts Q Q. This slide P is mechanicallyoperated by double-throw switch S constitutes a revers- It will thus beseen the valve-gearing in such a manner that the circuit is broken andthe magnetic clutch B deenergized and opened at the instant the valvebecomes tight shut or fully open.

The operation of this arrangementis as follows: Suppose the valve to betight shut and it is desired to open the same. First, the double-throwswitch is thrown into the position which will produce the desireddirection of rotation of the motor A. The motor is then brought to fullspeed by means of the starting-box 9. As no current is now flowingthrough the clutch B (the clutch-circuit be ing broken at the switch 10and at the contact device or slide P) the motor continues to run withoutoperating the clutch. If now the spring-retracted hand-switch 10 isclosed,thus

completing the circuit X through the clutch B, the clutch will operateso that the movement of the motor will be transmitted through thegearing and the valve will begin to open. As soon as the valve hasstarted to open the slide P will make contact with the plates Q Q, thuscompleting a circuit for the magnetic clutch Bin addition to the circuitthrough the s pring-retracted switch 10. It is nowno longer necessary tokeep the spring-retracted switch 10 closed. The attendant, therefore,releases it and its spring 1% throws it open. The motor continues toopen the valve until the slide P leaves the conducting-strips Q Q, andthus automatically breaks the circuit through the clutch, the partsbeing so proportioned that this will take place when the valve is fullyopen. The valve-stem will now cease to revolve, although the motor willcontinue to run untilit is stopped bythe opening of the do ublethrowswitch S. The operation in closing the valve is the same, except thatthe main or double-throw switch is placed in the opposite position, soas to reverse the motor, in which case the motor operates the valve-stemuntil the contact I? breaks connection at the other ends of theconducting-strips Q Q.

It will thus be seen that the power of the motor is automaticallyremoved from the va1vestem at the desired points both in opening andclosing the valve and that the danger to the apparatus is reduced to aminimum.

That I claim is 1. In combination a device having a limited range ofmovement, a motor for operating the same, an electrically-operatedclutch between said motor and said device, a self-opening switch forcompleting the clutch-circuit and a contact device moving withsaiddevice for breaking said circuit.

2. In combination,a device having a limited range of movement, a motorfor operating the same, an electrically-operated clutch between saidmotor and said device, a spring-retracted switch for completing theclutch-circuit, and a contact moving with said device for breaking saidcircuit.

3. In combination, a device having a limited range of movement, anelectric motor for operating said device, an electrically-operatedclutch between said motor and said-device, a spring-retracted switch insaid clutclrcircuit, and means moving with said device for breaking saidcircuit at the proper times, and a reversing-switch for said motor.

4. In combination,a device havingalimited range of movement, a motorA,an electricallyoperated clutch B, a spring-retracted switch 10 and acircuit-breakin g device K, said switch 10 and device K controlling theclutch I3.

SAMUEL GILBERT COLT.

\Vitnesses:

HERBERT W. SMITH, JOHN F. KELLY.

